Syncookie threshold 2999 exceeded

Folks,

During peak window we have noticed following logs on our LTM

Syncookie threshold 2999 exceeded, virtual = 74.201.103.192:443

Syncookie HW mode activated, server = 74.201.103.192:443, HSB modId = 2

I am reading this doc https://support.f5.com/csp/article/K14779?sr=56306627

Quote

"The SYN cache threshold is governed by the pvasyncookies.virtual.maxsyncache database variable. It defines the maximum number of outstanding SYN a virtual server can hold per TMM before the SYN cookie protection mechanism is activated. The default value of this threshold is 1993 (For 11.3.0 - 11.6.1) and 2999 (For 12.0.0 and later)."

We are running 12.0.0 so that is what i am seeing 2999 limit in logs, Default global setting is 16384

How do i increase threshold of

pvasyncookies.virtual.maxsyncache

?